Bug 1108771 - Part 1: Prompt for which application to bootstrap. r=gps

This lays the foundation for adding support for bootstrapping
mobile/android.

* Queries for which application to bootstrap, currently browser or
  mobile/android;

* Adds call to install_APPLICATION_packages after
  install_system_packages;

* Adds call to suggest_APPLICATION_mozconfig after bootstrapping
  everything;

* and splits install_browser_packages out of install_system_packages
  throughout (essentially untested, but generally simple).

To implement a new application (b2g?), just add it to the list of
applications and implement install_b2g_packages throughout.

--HG--
extra : rebase_source : 8c9b4485dbe5ceb64436fd73ea0258592a2b818f
Bug 1108771 - Part 2: Implement |mach bootstrap| for mobile/android on Debian-like systems. r=gps

This adds a generic android Python module that handles:

* downloading and unpacking Google's Android SDK and NDK bundles;
* using the |android| tool to install additional Android packages;
* printing a mozconfig snippet suitable for mobile/android builds.

--HG--
extra : rebase_source : abaffcee70eacb391f53d622fba4a445277818db
Bug 1108771 - Part 3: Factor _ensure_*_packages out of OS X bootstrapper. r=gps

This prepares the way for implementing install_mobile_android_packages
on OS X.

--HG--
extra : rebase_source : b52b7080f857e351e71f169f09a42dfd61b43a43
Bug 1108771 - Part 4: Implement |mach bootstrap| for mobile/android on OS X with homebrew. r=gps
Pushing on a CLOSED TREE because this is NPOTB.

The custom brew formula is a lightly edited version of an earlier
revision of brew's android-ndk.rb.  It's not clear that using a custom
brew formula for the Android SDK version r8e is better than using the
existing android Python module for installing the SDK and the NDK, but
it's done now and works locally.  If we really wanted to avoid shipping
it, we could probably arrange to land it in
https://github.com/Homebrew/homebrew-versions.

I see no easy way to install the Java 1.7 JDK with macports, so in the
spirit of the good now being better than the perfect later, I've
punted.  (I don't see an Android NDK package either, but that
functionality exists in Python.)  Patches wanted!

--HG--
extra : rebase_source : d3ca836951b05eb30fabc17e523676d31c1ec0ef
extra : amend_source : d34e9eb5cd840b827a7ce65a0d22c1c275efff09